ML20034F450

Annual Operating Rept,1992

ML20034F450
Person / Time
Site:	Wolf Creek
Issue date:	12/31/1992
From:	Maynard O WOLF CREEK NUCLEAR OPERATING CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
WO-93-0025, WO-93-25, NUDOCS 9303030216
Download: ML20034F450 (12)

Text

,

m WOLF CREEK

' NUCLEAR OPERATING CD ioORATION l

l l

Otta L. Maynard i

Wee President Plant Operations l

February 22, 1993 l

WO 93-0025 i

U. S. :Iuclear Regulatory Commission

'i ATTN: Document Control Desk Mail Station Pl-137 Washington, D. C.

20555 i

Subject:

Docket No. 50-482:

1992 Annual Operating Report for Wolf Creek Nuclear Generating Station Gentlemen:

The attached Annual Operating Report is being submitted pursuant to Wolf Creek 4

Generating Statien, Unit No. 1 Technical Specifications 6.9.1.4 and 6.9.1.5.

Also included in this report is information required by 10 CFR 20.407.

This report covers operations for the period of January 1, 1992 to December 31, 1992.

Very truly yours,

{

Otto L. Maynard l

Vice President i

Plant Operations i

OLM/jad Attach:aent t

cc:

J. L. Milhoan (NRC), w/a G. A. Pick (NRC) w/a W. D. Reckley (NRC), w/a T. F. Stetka (NRC), w/a j

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i P O Box 411/ Burhngton, KS 66839 / Phone. {316,

• 331 9303030216 921231 An Eaual opportunity Employer M T/NC/ VET PDR ADDCK 05000482 i

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Attachment to WO 93-0025 4

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WOLF CREEK NUCLEAR OPERATING CORPORATION WOLF CREEK GENERATING STATION l

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DOCKET NO:

50-482 FACILITY OPERATING LICENSE:

NPF-42 i

l ANNUAL OPERATING REPORT I

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REPORT NO. 8 l

l Reporting Period: January 1, 1992 through December 31, 1992 I

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Prepared by: Merlin G. Willians l

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1 Attachment to WO 93-0025

,Page 2 of 11 EXECUTIVE

SUMMARY

j The purpose of the Annual Operating Report is to provide a comprehensive i

summary of the operating experience - at Wolf Creek Generating Station.

}

The Annual Operating Report also provides a summary of the major safety related maintenance activities completed during the year.

This report covers the period beginning on January 1, 1992 and ending'on December

{

31, 1992.

i The Annual Operating Report is submitted in accordance with the requirements of Technical Specification 6.9.1.4 and contains -the information required by Technical Specification 6.9.1.5.

The format of this report is similar to that provided in Regulatory Position c.1.b of l

Regulatory Guide 1.16, Revision 4, August, 1975.

j Also included in this report is the information on personnel monitoring as required by 10 CFR 20.407.

l In 1992, Wolf Creek Generating Station's availability factuc was 85.8 j

percent and capacity factor (using maximum dependable capacity) was 85.5

[

percent.

Wolf Creek Generating Station experienced two unplanned reactor trips in 1992 after the unit was returned to aervice on January 20, 1992, following the completion of the fifth refueling outage.

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i Attachment to WO 93-0025 Page 3 of 11 1.

SUMMARY

OF OPERATING EXPERIENCE A summary of Wolf Creek Generating Station's operating experience and major safety related maintenance activities completed during 1992 is provided by month below.

This information has been previously submitted in accordance with the requirements of Technical Specification 6.9.1.8 in the Monthly Operating Reports for January through December, 1992.

January The unit completed its fifth refueling outage and the generator output braaker was closad on January 15, 1992 at 0004 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

Power ascension activities then took place, with the unit reaching full power at 1840 hours0.0213 days <br />0.511 hours <br />0.00304 weeks <br />7.0012e-4 months <br /> on January 20, 1992.

The unit operated at or near 100 percent power throughout the remainder of the month.

Majar safety related maintenance activities for January:

a.

Inspection,

testing, and evaluation of motor operated valves.

b. Deplacement of Residual Heat Removal discharge relief valve EJ8856B.

February The unit operated at 100 percent power throughout the month of i

February until an unplanned reactor trip occurred February 19, 1992 at 2110 hours0.0244 days <br />0.586 hours <br />0.00349 weeks <br />8.02855e-4 months <br /> as a result of the failure of an electronic component in inverter NNil and the subsequent loss of control power to both main feedwater pumps.

(This event was reported as Licensee Event Report 492/92-002-00).

While the unit was down, an inspection of the reactor vessel revealed that some minor leakage existed on three reactor vessel penetrations.

The unit remained down for the duration of the month as these items are repaired.

l Major safety related maintenance activities for February:

a. Replacement of circuit board in inverter NN11.

b. Replacement of main steam safety valve ABV057.

c. Repair of minor leakage on in-core thermocouple conduit.

d. At month's end, investigation into repair of reactor vessel canopy seal weld leakage was ongoing.

March After an unplanned reactor trip on February 19, 1992, the unit remained shutdown until March 27, 1992.

While the unit was shutdown, repair of the reactor vessel canopy seal weld and the reactor cavity seal ring was performed. An investigation of an unexplained noise that occurred on February 28, 1992 identified that the Reactor Coolant System crossover leg saddles were coming in contact with the thrust block shims.

The investigation also identified the need to rework the Loop A and C vertical drop restraints.

(This event was reported as Licensee Event Report 482/92-006-00 and was further discussed in NRC Information Notice 92-86, dated 12/24/92).

The unit

Attachment to WO 93-0025 Page 4 of 11 reached full power at 2234 hours0.0259 days <br />0.621 hours <br />0.00369 weeks <br />8.50037e-4 months <br /> on March 28, 1992 and remained at full power for the remainder of the month.

Major safety related maintenance activities for March

a. Repair of the reactor canopy seal weld leakage.

b. Repair of reactor cavity seal ring.

c. Adjustments to the Loop A and C Reactor Coolant Pump vertical drop restraints and the thrust block shims.

April The unit operated at or near 100 percent pow)r throughout the month of April.

No major safety related maintenance activities were performed during the month of April.

May The unit operated at or near 100 percent power throughout the month of May.

No major safety related maintenance activities were performed during the month of May.

June The unit operated at or near 100 percent power throughout the month of June.

No major safety related maintenance activities were performed during the month of June.

Julv The unit operated at or near 100 percent power throughout the month of July.

No major safety related maintenance activities were performed during the month of July.

Aucust The unit operated at or near 100 percent power throughout the month of August with the exception of a power reduction following the loss of a 345 kilovolt (kV) line.

The power reduction occurred on August 11, 1992, following the loss of the 345 kV Lacygrie line to ensure that grid stability would be maintained if a second line was lost.

Power was reduced to 80 percent for approximately 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

Power was returned to 100 percent after the 345 kV line was returned to service.

No suajor safety related maintenance activities were performed during the month of August.

September The unit operated at or near.100 percent power throughout the month of September.

l Attachment to WO 93-0025 Page 5 of 11

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No major safety related maintenance activities were performed during the month of September.

October The unit operated at or near 100 percent power throughout the month of October.

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No major safety related maintenance activities. were performed i

during the month of October.

November The unit operated at or near 100 percent power until November 10, 1992, at 1105 hours0.0128 days <br />0.307 hours <br />0.00183 weeks <br />4.204525e-4 months <br />, when a reactor trip occurred due to a ground fault at an off-site substation.

The fault was caused i

by contact between an overhead ground and the energized portion of a 138 kV ring bus during clearance procedures for a 345/138 kV transformer at the substation.

Non-nuclear utility personnel were performing the work at the substation. The unit was in Mode 3, Hot Standby, following the trip.

(This event was reported as Licensee Event Report 482/92-016-00).

On November 11, 1992, at 0330 hours0.00382 days <br />0.0917 hours <br />5.456349e-4 weeks <br />1.25565e-4 months <br />, the unit entered Mode 2, Startup.

Mode 3, Hot Standby, was reentered at 0436 hours0.00505 days <br />0.121 hours <br />7.208995e-4 weeks <br />1.65898e-4 months <br /> due to Digital Rod Position Indication problems.

At 1244 hours0.0144 days <br />0.346 hours <br />0.00206 weeks <br />4.73342e-4 months <br />, the unit entered Mode 2 following repairs to the Digital Rod Position Indication system.

Mode 1,

Power Operation, was entered at 1608 hours0.0186 days <br />0.447 hours <br />0.00266 weeks <br />6.11844e-4 months <br />.

On November 13, 1992, at 1310 hours0.0152 days <br />0.364 hours <br />0.00217 weeks <br />4.98455e-4 months <br />, the unit was returned to 100 percent reactor power.

The unit operated at or near 100 percent power throughout the remainder of the month.

No major safety related maintenance activities were perforaned during the month of November.

December The unit operated at or near 100 percent power throughout the month of December.

j No major safety related maintenance activities were performed during the month of December.

T 2.

SUMMARY

OF OUTAGES AND FORCED POWER REDUCTIONS Provided below is a summary of the 1992 outages and forced power reductions of over 20 percent of design power level where the reduction extended for more than four hours. References to reports of reportable occurrences directly related to each outage or load reduction are included in parenthesis where applicable.

1. Start Date: 01/01/92 Completion Date:

01/15/92 Tvoet Forced puration:

336.1 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> 1

Reasons _

Continued forced outage for resolution of motor operated valve issues which were discovered during the fifth refueling outage.

Attachment to WO 93-0025 I

Page 6 of 11 i

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2. Start Date: 02/19/92 completion Date: 03/27/92 i

• ype: Forced Duration:

877.4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />

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Peason:

Unplanned reactor trip at 2110 hours0.0244 days <br />0.586 hours <br />0.00349 weeks <br />8.02855e-4 months <br /> February 19, 1992, on steam generator lo-lo level as a result of an electronic component failure in i

inverter NN11 and the subsequent loss of control l

power for both main feedwater pumps.

(Reported as Licensee Event Report 482/92-002-00).

While i

the unit was shutdown, the reactor vessel canopy 3

seal welds and the reactor cavity seal ring were t

repaired. Also, adjustments to the Loop A and C i

Reactor Coolant Pump vertical drop restraints f

and the thrust block shims were performed.

(Reported as Licensee Event Report 482/92-006-i 00).

3. Start Date: 11/10/92 completion Date:

11/13/92 Typet Forced Duration:

30.9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> i

Feason:

Unplanned reactor trip at 1105 hours0.0128 days <br />0.307 hours <br />0.00183 weeks <br />4.204525e-4 months <br /> on November 10, 1992, when a ground fault was inadvertently initiated by contact tetween an overhead ground and the energized por 4on of a 138 kV ring bus at an off-site substation by non-nuclear utility bO).

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l Attachment to WO 93-0025

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EXPOSURE INFORMATION I

a.

NUMBER OF PERSONNEL AND MAN-REM BY WORK AND JOB FUNCTION REPORT - 1992 i

NUMBER OF PERSONNEL (>100 MREM)1 TOTAL MAN-REM 2 WORK & JOB FUNCTION STATION UTILITY CONTRACT STATION UTILITY CONTRACT Reactor Operations & Surveillance 1

Maintenance & Construction 1

0 4

1.261 0.015-1.268 operations 0

0 0

1.093 0.006 0.073 Health Physics & Lab 20 0

0 5.653 0.264 0.233 Supervisory & Office Staff 1

0 2

1.447 0.024

'O.798 Encineerino Staff 4

0 2

1.459 0.288 0.935 Routine Plant Maintenance Maintenance & Construction 0

0 0

1.398 0.015 1.152 Operations 0

0 0

0.135 0.000 0.000 Health Physics & Lab 0

0 0

0.418 0.043 0.049

, Supervisory & Office Staff 0

0 0

0.409 0.000 0.063

__Encineerino Staff 0

0 0

0.416 0.019 0.010 Inservice Inspection Maintenance & Construction 1

0 16 0.469 0.019 3.734 operations 0

0 0

0.268 0.000 0.000 Health Physics & Lab 3

1 0

0.869 0.121 0.000 Supervisory & Office Staff 9

0 1

2.368 0.000 0.333

, Encineerino staff 6

3 4

1.442 0.389 1.184 1

Special Plant Maintenance Maintenance & Construction 10 2

80 3.583 0.343 26.018 1

. Operations 1

0 0

0.328 0.024 0.123 l

[HealthPhysics& Lab 4

0 1

1.422 0.067 0.295 Supervisory & Office Staff 4

0 4

1.428 0.000 0.836 Enoineerino Staff 1

0 1

0.581 0.039 0.256 i

Waste Processing Maintenance & Construction 0

0 0

0.029 0.000 0.121 Operations 0

0 0

0.051 0.000 0.019 i

Health Physics & Lab 5

0 0

3.802 0.000 0.000 Supervisory & Office Staff 2

0 0

0.275 0.000 0.000 Encineerino Staff 0

3 0

0.010 0.000 0.000 Refueling Maintenance & Construction 0

0 0

0.000 0.000 0.000 Operations 0

0 0

0.005 0.000 0.000 Health Physics & Lab 0

0 0

0.005 0.000 0.000 Supervisory & Office Staff 0

0 0

0.000 0.000 0.000 Encineerina Staff 0

0 0

0.000 0.000 0.000 Totals Maintenance & Construction 12 2

100 6.730 0.391 32.294 1

Operations 1

0 0

1.881 0.030 0.215 Health Physics & Lab 32 1

1 12.169 0.495 0.S77 Supervisory & Office Staff 16 0

7 5.927 0.024 2.030

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Enoineerina Staff Il 3

7 3.908 0.735 2.385 i

Grand Totals 72 6

115 30.615 1.675 37.500 i

i 1Number of personnel > 100 mrem based on Pocket Ion Chamber (PIC) data i

2Total man-rem based on ratio of PIC data applied to TLD data 5

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Attachment to WO 93-0025 Page 8 of 11 i

i b.

PERSONNEL MONITORING REPORT 1.

In 1992, 1103 individuals were provided personnel monitoring j

devices. This information is provided in accordance with 10 CFR 20.407(a)(2)..

This total includes the number of l

individuals required to be reported under 10 CFR 20.407(a)(1).

2.

Below is a statistical summary report of the personnel monitoring information recorded for individuals for whom personnel monitoring was provided in 1992 in accordance with the requirements of 10 CFR 20.407(b).

)

Estimated whole body exposure range Number of individuals (reme) in each range i

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No measurable exposure..

................................657 t

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Measurable exposure less than 0.1........................

304 f

i 0. 1 t o 0. 2 5............................................... 61 i

t 0.25to0.5...............................................45 i

i 0.5 to 0.75...............................................

17 t

0.75to1.0...............................................7 I

i 1.0to2.0................................................12 l

I 2.0 to 3.0................................................

0 3.0 to 4.0................................................

0 f

4.0 to 5.0.................................................O i

5.0 to 6.0................................................

0 6.0 to 7.0................................................

0 i

7.0 to 8.0.................................................O F

8.0 to 9.0.................................................O F

9.0 to 10.0...............................................

0 10.0 to 11.0..............................................

0 11.0 to 12.0...............................................O l

Greater than 12.0..........................................O i

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Attachment to WO 93-0025 Page 9 of 11 l

4.

SINGLE RELEASE OF RADIOACTIVITY OR RADIATION EXPOSURE GREATER THAN 10 FERCENT O/ ALLOWABLE ANNUAL VALUES During 1992, there wac no single release of radioactivity greater than ten percent of the allowable annual value.

On March 26, 1992, while the unit was shutdown, an engineer in the Radiologically Controlled Area was discovered to have a localized area of contamination on the left cheek.

The contamination was determined to be a hot particle which probably originated from work previously performed which required breaching the Reactor Coolant System.

It was subsequently determined that the particle was made of stellite and, given its strength and geometry, the l

exposure was calculated to be 15.9 Rem to the skin of the whole body.

This exposure exceeded the 10 CFR 20.301 quarterly dose limit and represented 53 perc*nt of the annual allowable exposure limit to the skin of t.he who'e body for an individual.

(This event was reoorted as Licenset Event Report 482/92-007-00 and supplement 482/92-007-01).

I 5.

CHALLENGES TO THE PORVS AND SAFETY VALVES During 1992, there were no challenges to the Pressurizer Power Operated Relief Valves (PORVs) or safety valves.

However, PORV BBPCV456A has been

isolated, per Technical Epecification 3.4.4.a, due to excessive ceat leakage, since May 5, 1992.

6.

INDICATIONS OF FAILED FUEL During August / September 1992, detailed inspect i ons were performed of the failed fuel assemblies that were di. overed during the fifth refueling outage.

(Reference Licensee Event Report 482/91-019-00).

The intent of the inspections was to confirm the grid-to-rod fretting as the failure mechanism and to ascertain the root cause of the failure mechanism.

From these additional

~

inspections it was confirmed that grid-to-rod fretting was the principle failure mechanism.

It was determined that fuel handling or fuel fabrication issues are unlikely root causes and that the fuel assenblies were fabricated to current design specifications.

Investigation into the possibility that the root cause of the failure of the fuel assemblies was related to flow characteristics i

in the core is ongoing.

The current iodine activity in the Reactor Coolant System (RCS) indicates that there are 2 defective fuel rods in the core.

However, noble gas activity in the RCS indicates that there are 6 - 10 defective fuel rods.

This activity level meets the requirements of Action Level 1 per procedure ADM 01-221, " Failed Fuel Action Plan."

Action Level 1 is defined as a moderate increase in RCS Activity level beyond that defined for normal operation and sustained at steady-State Operation for more than seven days.

This action level requires, in part, an assessment of plant operating data to develop an initial estimate of the number and type of fuel failure, a review of fabrication and other design records, and the initiation of plans for end-of-cycle fuel inspections, assembly reconstitution or replacement, and root cause evaluation.

Attachment tc WO 93-0025 J

Page 10 of Il j

7.

REACTOR COOLANT SYSTEM SPECIFIC ACTIVITY IN EXCESS OF TECHNICAL j

SPECIFICATION 3.4.8 LIMITATION j

On November 10, 1992, following a reactor trip, it was determined through analysis that the specific activity of the RCS had j

exceeded the Technical Specification (T/S) 3.4.8.a limit of 1 I

microcurie per ml Dose Equivalent I-131 (DEI).

The analysis results of the sample taken at 1316

CST, indicated 1.011 microcuries per ml DEI.

Maximum cleanup flow through the Chemical and Volume Control System (CVCS) mixed bed demineralizer was maintained during the time that the specific activity exceeded the T/S limit.

The DEI was back within the limits of T/S 3.4.8.a by 1412 CST.

J The following information is provided in accordance with T/S 6.9.1.5.c:

1 a.

Reactor power history starting 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> prior to the first sample in which the limit was exceeded:

From November 8,

1992, at 1316 CST, until 1103 CST on November 10, 1992, Reactor power was approximately 100 percent.

Following a reactor trip at 1103 CST, until 1316 CST, Reactor power was O percent.

b.

Results of the isotopic analyses for radiciodines Sample 1-131 1-132 1-133 I-134 1-135 DEI PATE & TIME UC1/ML UC1/ ML UC1/ML UCI / M L UC1/ML UC1/ML j

11/09/92 1106 2.7 9 9E-0 3 3.10SE-02 1.595E-02 5.293E-02 2.923E-02 1.160E-02 11/10/02 0831 2.7eiE-03 3.1720-02 1.616E-02 5.342E-02 2.903E-02 1.170E-02 1

11/10/92 1316 7.710E-01 5.125E-01

6. 7 53E-01 1.200E-01 4.425E-01 1.011 11/10/92 1417 7.425E-01 4.675E-01 6.351E-01 6.330E-02 4.048C-01 9.661E-01 11/10/92 1520 6.755E-01 4.013E-01 S.6090-01 3.255E-02

3. 0 97 E-91 8 600E-01 11/10/92 1533 6.632E-01 4.0270-01 5.426E-01 2.459E-02 2.950E-01

8. 4 96E-01 j

l c.

Cleanup system flow history starting 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> prior to the first sample in which the limit was exceeded:

The cleanup flow through the CVCS mixed bed demineralizer was approximately 110 gallons per minute for the 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> prior to exceeding the limit of 1 microcurie per gram. This cleanup flow was maintained while the DEI I-131 limit was exceeded.

d.

Time duration when the specific activity of the primary coolant exceeded the radiciodine limit:

The specific activity of the RCS exceeded the T/S 3.4.8.a limit of 1 microcurie per gram Dose Equivalent I-131 for 56 minutes.

This occurred from 1316 CST until 1412 CST, on i

November 10, 1992.

e.

Graph of the I-131 concentration and one other radioiodine isotope concentration in microcuries per gram as a function of time for the duration that the specific activity was above the steady-state level:

i See Graph 3:

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